Blast furnace bosh lining support



&809.007

Oct. 8, 1957 v M. T HElL BLAST FURNACE BOSH LINING SUP'PORT Filed Dec. 23, 1953 I II/ l /l/ /ll 2,809,007 BLAST FURNACE BOSH LINING SUPPORT Martin Theil, Youngstown, Ohio, assignor to United States Steel Corporation, a corporation of New Jersey Application December 23, 1953, Serial No. 399,871

4 Claims. (Cl. 248-201) This invention relates to an apparatus for supporting the bosh lining of a blast furnace while its hearth is being repaired or replaced.

When the hearth of a blast furnace is in need of repair or replacement, it becomes necessary to provide a support for the bosh lining. In accordance with conventional practice, the bosh lining is customarily supported during hearth repair or replacement by either of two types of apparatus. In one type, supporting brackets are welded to the inner surface of the furnace shell and their outer ends are supported by cables which are strung from the top of the furnace. In this type, the brick work of the lining is removed at a point below the bosh so that the supporting brackets may be welded to the inner surface of the furnace shell, and the top furnace Components including the large bell, small bell, distributo', must be removed in order that the supporting cables can be installed. The brackets welded to the inside of the furnace shell are generally twelve in number and twelve additional brackets are arranged alternately with respect to the welded brackets and these additional brackets extend through openings in the furnace shell so that their outer ends are supported on the shell. The openings through which the additional brackets extend may be cut through the body of the shell or may be cooling plate openings already in the shell. All of the brackets of course have their inner ends supported by the cables depending from the top of the furnace.

In the other type of support, beams are inserted through diametrically opposed tuyere holes and the bosh brick work is supported on these beams by means of Wood blocks. These beams eXtend diametrically across the interior of the furnace and, due to their length, have considerable flexibility.

The elasticty of the supporting cables in the first type and the flexibility of the beams in the second type present a distinct disadvantage in that sudden loads applied to these supporting Components will result in movement of the bosh and stack linings and the production of cracks in the lining requiring further repair. This is particularly true when blasting is required to remove salamander in the hearth bottom. In addition, both types are undesirable from the standpoint of the time and work required to efiect their installation and removal.

One of the principal objects of this invention is to provide an improved support which is infiexible and which will not permit movement of the bosh lining when the support is subjected to sudden loads of shock proportions such as are encountered when the hearth is blasted. A further object is to provide an improved bosh lining support in which the components are of smaller size as compared to conventional types of bosh lining supports and which will reduce the time and labor required for installation and thereby reduce the out-of-operation" period of the furnace for repair purposes.

Other objects and advantages of the invention will become apparent from the following description.

In the drawings, there is shown a preferred embodiment of the invention. In this showing:

Figure 1 is a fragmentary and vertical sectional view of a blast furnace illustrating diagrammatically the manner in which the braced beam supports of this invention are applied to the tuyere openings in a blast furnace;

Figure 2 is an enlarged vertical sectional view taken centrally of one of the furnace tuyere openings illustrating in detail the supporting structure of this invention; and

Figure 3 is a fragmentary perspective view looking from the interior of the furnace and showing the manner in which the bosh lining of the furnace is supported by the supporting structure of this invention.

In Figure l of the drawings there is shown a conventional and diagrammatic illustration of a blast furnace comprising a stack 1, a bosh 2 and a hearth 3. Tuyere openings 4 at the bottom of the bosh 2 are utilized for the mountng of supports in the nature of braced beams, respectively designated as a whole by the numeral 5, of this invention.

The structure of the braced beams 5, and their manner of installation, will be best understood by referring to Figure 2. In this showing, the numeral 6 designates the tuyere jacket constituting part of the furnace shell. The jacket 6 has the usual tuyere openings 4 therein which have annular collars or lips '7 extending inwardly from the inner surface of the shell. The numeral 8 designates a conventional bosh band which is supported on the tuyere jacket by a bosh band support 9.

The braced beams 5 inserted through each opening 4 comprise an L-shaped member 10 having a horizontal leg 11 and a vertical leg 12. The vertical leg 12 is welded at 13 to the external surface of the tuyere jacket 6 at the top of one of the tuyere openings 4 to provide a support for the outer end of the leg or beam 11 which extends inwardly through a tuyere opening 4 in a direction radially of the furnace and has a length such that its inner end 14 extends beyond the inner surface of the bosh lining 2 to be supported. The inner end of the beam 11 is supported by a brace 15 which extends angularly inwardly and upwardly relative to the furnace and has its upper end welded as at 16 to the undersurface of the beam 11 adjacent its inner end 14. The lower end of the brace 15 has a notch 17 in which the inner edge 18 of the collar 7 is received to provide a support for the brace 15 at the bottom of the opening 4 and vertically below the beam connection 13. The member 10 and the brace 15 are preferably fabricated by cutting four inch slabs of metal to the shapes illustrated.

Figure 3 illustrates the maune-r in which the braced beam supports 5 are arranged in adjacent tuyere openings 4. When a pair of braced beam supports 5 are installed in adjacent tuyere openings 4, a portion of the bosh brick work 2 above and between the openings 4 is removed so that a metal plate 29 may be inserted to a position in which it is supported on the upper surfaces of the beams 11. The supporting plates 20 have a length such that their opposite ends extend to a point substantially centrally of the beams 11. The plates 20 are welded as at 21 to the upper surfaces of the beams 11. After the plates 20 have been inserted in position and' welded to the beams 11, Wood blocks 22 are wedged in position between the plates 20 and the undersurface 23 of the bosh lining to provide a support therefor. While the above description has proceeded on the basis that each braced beam 5 is installed in position before the removal of any brick work, it will be understood that a portion of the brick work above each tuyere opening 4 may be removed initially to facilitate mounting of each brace beam 5 in position.

In practice, installation of the support 'of this invention Patented Oct. 8, 1957 is started at several points about the circumference of the furnace. The points of starting preferably are four in number spaced at 90 intervals. As soon as two of the braced beams 5 are installed in adjacent tuyere openings 4 -at any of the starting points, a supporting platc 20 is welded in position on the beams 11 as described above and the bottom portion of the bosh brick work Z is supported on the plates 20 by the Wood blocks 22. Installation of the support is thercafter continued from each of the starting points by mounting another of the i braced beams 5 in position to provide a support for another plate 20 and a further series of supporting ble-eks 22. The installation is continued in this manner from each of the starting points until the support is continuous about the circumference of the furnace.

From the foregoing, it will be noted that the bosh lining is supported by the braces 5 -on the tuyere jacket 6 which constitutes part of this furnace shell. The tuyere jacket is preferably provided with braces (not shown) extending between its outer surface and supporting columns or other convenient structure to prevent its being sprung outwardly by the weight of the 'brick work supported thereon.' Attention is particularly directed to the fact that the braced beams 5 are infiexible and provide a rigid support which will not move when subjected to forces of shock proportions such as are encountered when the furnace hearth is subjected to a blasting operation. In this manner, the development of cracks in the bosh and stack linings which would otherwise require subsequent repair is elfectively prevented. Attention is also directed to the fact that the size of the components forming each braced beam 5 and of the supporting plates 20 is reduced to a minimum thereby redu-cing the labor and the size of the handling equipment required to effect their installation as Compared to the conven- 7 tional types of supports referred to above. In this manner, the time required to repair or replace a hearth is materially reduced as Compared to conventional practice. The "out-of-operation period of a blast furnace during repair or replacement of the furnace hearth has been reduced 'by as much as two weeks by the use of the support of this invention as compared to the time required to repair or replace a hearth when using the conventional types of support referred to above.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

l. An apparatus for supporting the bosh lining of a blast furnace having a furnace shell with tuyere openings therein comprising; a plurality of horizontal beams respectively extending through different ones of said openings in a direction radially of the furnace and having supporting connections at their outer ends with the shell adjacent the tops of the openings through which they respectively extend, each of said beams being provided With a supporting brace having supporting engagement at its lower end on said shell at the bottom of one of said openings and having a supporting connection at its upper end with the beam braced thereby, each of said *braces extending angularly inwardly and upwardly from the bottom of one of said openings with respect to the furnace, and supporting plates carried by said beams and positioned underneath and providing a support for the bosh lining.

2. An apparatus for supporting the bosh lining of a blast furnace having a furnace shell with tuyere openings therein comprising; a beam of L-shape, said 'beam having a vertical leg provided with a Welded connection to the outer surface of the shell in an area at the top of one of said openings and a horizontal leg projecting through said one opening in a direction radially of the furnace, and a brace having 'supporting engagement with the shell at the bottom of said one opening, said brave extending angularly inwardly and upwardly of the furnace and having a supporting connection at its upper end with said horizontal leg.

3. A temporary support for the bosh lining of a blast furnace during repair of its hearth comprising; a horizontal platform formed of a plurality of supporting plates and on which the bosh lining is supported, a tuyere jacket having a plurality of tuyere openings at uniformly spaced intervals thereabout, a plurality of horizontal beams respectively extending in a direction radially of the furnace and having supporting connections at their outer ends with said jacket adjacent the tops of said openings, each of said beams being provided with a brace having supporting engagement at its lower end on said jacket at the bottom of one of said openings and having its upper end in supporting engagement with and adjacent the inner end of the beam braced thereby, each of said braces extending angularly inwardly and upwardly from the bottom of one of said openings with respect to the furnace, said supporting plates being mounted on said beams whereby said jacket provides a support for said platform and the bosh lining carried thereby.

4. A temporary support for the bosh lining of a blast furnace during repair-of its hearth comprising; a horizontal platform formed of a plurality of slabs arranged in end to end relation and on which the bosh lining is supported, a tuyere jacket having a plurality of tuyere openings at uniformly spaced intervals thereabout, said slabs being positioned about the inner surface of said jacket with the facing ends of adjacent pairs of slabs positioned along lines extending radially inwardly of the furnace from the top of one of said tuyere jacket openings, and a plurality of horizontal beams respectively positioned under different ones of said lines and having supporting engagement with the ends of an adjacent pair of slabs, each of said beams extending in a direction radially of the furnace and having a supporting connection at its outer end with said jacket adjacent the top of one of said tuyere openings, each of said beams being provided with a brace having supporting engagement at its lower end on said shell at the bottom of one of said tuyere openings and having its upper end in supporting engagement with and adjacent the inner end of the beam braced thereby, said beams and braces thereby providing a support for said platform and the bosh lining carried thereby on said tuyere jacket.

References Cited in the file of this patent UNITED STATES PATENTS 76,232 Morse Mar. 31, 1868 353,'763 Trafton Dec. 7, 1886 2,577,979 Pierson Dec. 11, 1951 

